Wind does not chill the temperature, it removes energy faster

Q: A friend of mine and I disagree. I said wind chill factor only refers to how the air feels versus the actual ambient temperature. He insists that a thermometer can show wind chill. I said no, that if you had two thermometers on the same side of the house, one exposed to the wind and one not exposed to the wind, that both would indicate the same temperature, even if the wind chill was 20 degrees lower than the ambient temperature. He thinks the temperature of the thermometer in the wind would be lower. Which one of us is right?

A: I think you will be happy with my answer, as you are more correct than your friend. I always say that the wind chill is one of the most misunderstood things when it comes to the weather.

Wind does not lower the actual temperature. What the wind does do is to remove energy from an object faster than still air would. Therefore, if we warmed both thermometers to 70 degrees and then put one out in 35 degrees with wind and the other in 35 degrees without wind, the one in the wind would cool to 35 degrees quicker.

However, in time, they both would read 35 degrees and cannot reach any lower. There is a chance that your buddy has one of those automated weather stations that report wind and temperature. Such stations will then calculate a wind chill temperature from the measured temperature and wind.

This is a good time to tell people that the formula for wind chill was changed in November 2001; therefore, one station built before that time would read a different wind chill from one built after that date.

Q: Where is the best direction to put a thermometer — north, south, east or west?

A: I am assuming that you are talking about on which side of the house you should put your thermometer. The best answer I have for you is none of the above. The placement of a thermometer is more important than the type of thermometer and near a house is not a good location.

An official thermometer is usually placed in a white, vented shelter about five feet from the ground and away from any objects such as trees or buildings. This allows for the thermometer to measure the temperature of the air without being influenced by the sun or any other object that may be warmed from the sun.

Such objects (including the thermometer) absorb the sun’s energy more than the air, and what you end up with is the temperature of the object and not the air.

The worst places for a thermometer are on the west, east and south sides of a house. These are the sides of the house that get direct sunlight, and the actual temperature of the house will run much higher than on the north side of the house. In these cases, the thermometer will run way too warm.

The north side of the house is shady, but it still will run warm and not read the true temperature of the air. A porch is not a good place, as the sides and roof of the porch will radiate heat to the thermometer.

For a home hobbyist, putting a thermometer in a constantly shady spot away from the house is a best bet.

If you have a question about the weather, you can write to Joe Murgo at 5000 Sixth Ave., Altoona, PA 16602 or e-mail him at murgo@wtajtv.com. Some questions will be answered here, and all of the questions will be entered in a contest to be shown on WTAJ News at 5 p.m.

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